Telephone system.



F. x. STAUB. TELEPHONE SYSTEM.

APPLIOATIOH FILED APBJS, 1910.

Patented Nov. 29, 1910.

uvvsmon 2?;47275 ,K. 527a;

WITNESSES: 2%wm 3 ATTORNEY UNITED PATENT @ldlFlQE FRANK X. STAUB, OFFORT WAYNE, INDIANA, ASSIGNOR YES C-IJEJVIN LELEPHGNE MANUFACTURINGCOMPANY, OE CEJCILGO, ILLINQIS, A CORPORATION 05 ILLINOIS.

TELEPI-EGNE SYSTEM.

amiss.

Application filed April 8, 1910.

Specification of Letters Patent.

Serial No.

had to the accompanying drawings, forming a part of this specification.

My inven ion relates to telephone systems and has for its object theprovision of an improved circuit arrangement and apparatus wherebytelephone receivers equipped with soft iron readily magnetizable anddemagnetizable cores may be energized by means of direct current passedover the lines leading to the telephone stations including receivers. inaccordance with the preferred embodiment of my invention, when a line isidle, the soft iron-core receiver is not included in circuit with thesource of direct current but when this line employed for conversationalpurposes, the source of direct current is included in circuitwith thereceiver. The telephone transmitter at each station equipped with a softiron core receiver is desirably directly included in the telephone line,but I do not wish to beliniited to this characteristic. Multiply relatedpaths, each'serially included in the line, are provided at the telephonestation equipped with the soft iron core receiver, one of these pathsdesirably containing all of the receiver voice current winding while theother path is substantially non-inductive. The two multiply relatedpaths are so proportioned as to enable the source of direct: current,such as a battery, properly to magnetize the core of the receiver so asto make it perform the function of a permanent magnet and at the sametime be properly responsive to voice currents coming in over the line,the substantially non-inductive shunt permitting voice currentsimpressed. upon the line by the operation of the transmitter at the samestation with the receiver to be shunted away from the receiver windingto a sutlicient extent to enable them properly to be impressed upon theline, The substantially n0n-inductive shunt provided about the receiverwinding may be metallically continuous, in which case a noninductivecoil of a resistance which is desirably high with respect to thereceiver winding is provided.

' pref-erred, the non-inductive shunt may udc a condenser in place ofthe non-inductive coil.

will explain my invention more fully by reference to the accompanyingdrawing showing the preferred embodiment thereof, in which- Figure 1illustrates a telephone line extending from a substation to an exchangeand Fig. :2 illustra in y be found, for example, in interior sys tems.

Like parts are indicated by similar charactors of reference throughoutthe different iigures.

Referring first to the equipment illustrated in Fig. 1, have showntelephone inc whose limbs a L) extend from a telephone .tation A to anexchange B, the limbs 61 b terminating respectively in short and longline jack s irings 0 (Z that are illustrated respectively in engagementwith the tip and sleeve of a cord circuit plug 0. The cord circuitstrands include condensers f and g shunted respectively by the pair ofimpedance coils 7"" and the pair of impedance coils 5 a battery 71 offrom twenty to sixty volts or other suitable voltage having one poleconnected between the impedance coils f and the other pole connectedbetween the impedance coils g. l have not illustrated any more of thecord circuit apparatus nor any more of the line equipment, as suchapparatus is well known by those skilled in the art. When a jackreceives a plug thus connected with a source it of direct current, thecurrent may flow over the line, assuming that the telephone of such lineis removed from its switch hook, a switch hook 2' being illustrated atthe substation A. When the switch hook is relieved of the weight of thereceiver, it oins the two sides a Z) of the telephone line through atransmitter is and the winding Z of a telephone receiver seriallyrelated with the transmitter, this winding surrounding a soft ironreadily magnetizable and demagnetizablo core which is magnetized by thecurrent of the battery it to enable it to have the function of apermanent magnet and which is at the same time subject to incoming voicecurrents traversing the winding Z to enable the receiver telephonicallyto respond. A substantially non-inductive shunt circuit msurrounds thereceiver winding but is serially related with tes a telephone line suchas min the transmitter so as to reduce the iinpedance oti ered by thewinding}; Z to the voice currents impressed upon the line at thetransmitter 70, said shunt circuit being so proportioned to cause thevoice currents coining in to the receiver over the telephone lineproperly to pass through the receiver winding Z to occasion theeiiicient operation ot he receiver.

i the form of the invention illustrated in l, the substantiallynon-inductive shunt circuit inetallically continuous and include anon-incuctive winding; a that may be, for example. of five l'iundreclohins re sistance in event of the receiver winding;- Z being of onehundred ohms resistance. By the relative proportions of "esistancespecitied the receiver may readily be magnetized by direct current fromthe battery it and will, readily respond to incoming voice currentswhile the impedance ottered to outgoing voice currents is sutlicientlyreduced to enable the proper propagation of outgoing voice currents.

The arrangement shown in Fig. 2 is in all essential respects similar tothe arrangement shown in Fig, 1. the battery being connected directlywith the line thr ugh the inipedanco coils f 9 without the aid of plugand jack, wh le a; the telephone station eouippeo with a sort iron coretelephone receiver, the substantially non-inductive shunt about thereceiver winding Z includes a con denser 0 that may be of one haltinicrojtarad capacity in place of the substantially noninductive windinga belonging to the sys tem illustrated. in 1.

/Vhile it have herein. shown and particularly described the preferredembodiment of my invention, it do not wish to be limited era-r42 to theexact details of construction shown as changes may readily be madewithout departing; from the spirit of he invention, but

Having thus described my invention, I claim as iron: and desire tosecure by Letters Patentthc fOllOWiTlgZ-- 1. A telephone systemincluding a tele phone line having); a telephone station which includesa receiver having a soft iron readily mo 1 cable and denuignctizablecore provided will a winding; serially included with the line and withmeans at the same station with the receiver for impressing voicecurrents upon the line; a substantially non-indu'tive shunt aoout turnsoi:- the receiver winding and also serially related with said means; anda source of direct current included in circuit with the receiver windingby the telephone line.

2. A telephone system. inclu iling a telephone line having a telephonestation which includes a receiver h aving a soft iron. readily inagnetirzable and deniagnetizable core provided with a winding serially includedwith the line and with a transmitter at the 53211116 station with thereceiver for impressing voice currents upon the line; a substantiallynon-inductive shunt about turns of the re cciver winding and alsoserially related with said transmitter; and a source of direct currentincluded in circuit with the receiver winding and the transmitter at thesame station therewith by the telephone line.

In witness whereof, l hereunto subscribe my name this 2nd day of Aprilit. 1)., 1910.

X. STAUB.

li itnesses Enirnn It. ConwIN. M. :3. Laniiiirnn.

